Abnormal surges and the effects of the Seto Inland Sea circulation in Hiroshima Bay, Japan

A significant sea level rise, or abnormal surge, occurred in Hiroshima Bay approximately 8 days after a typhoon passed through the Seto Inland Sea (SIS) in September 2011. This event led to flooding at Itsukushima Shinto Shrine. Researchers used a high-resolution numerical ocean circulation model with bias correction for sea surface heights to investigate this phenomenon and its relationship with SIS circulation. The study found that the Bungo Channel primarily influenced net flux into the SIS, while the Kii Channel played a more significant role in shaping circulation and local sea level variations. The Kanmon Strait had minor impacts. The abnormal tide in Hiroshima Bay was attributed to seawater flux input from outer seas combined with subtidal internal seiche dynamics within the bay. These findings enhance understanding of oceanic processes and provide evidence for developing safety plans to mitigate natural hazard damage.

Jeong, J.-S., Lee, H. S., & Mori, N. (2024). Abnormal surges and the effects of the Seto Inland Sea circulation in Hiroshima Bay, Japan. Frontiers in Marine Science, 11. https://doi.org/10.3389/fmars.2024.1359288